Nanotech Arguments
Sep. 20th, 2004 01:36 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
selenite0The author of the nanofactory article I critiqued below and I have gone round a couple more times. This is my response to his latest comment:
Looking at thermionics--doesn't look proven to me. Great stuff if it works, but if it doesn't does the whole nanofactory concept collapse? No, you just have to use some tech that does work, and you should budget for it. There shouldn't be more than one breakthrough on the critical path, that's asking for disaster in a real project. In this case it's asking to be dismissed as an unrealistic handwaver. Given that you put zero as the mass of the cooling system (and other support systems) when calculating the reproduction time for the nanofactory I've still got doubts.
You'll be right far more often if you try to prove to yourself that it will be easy.
I'm not going to take an optimistic attitude looking at this stuff. Optimistic engineers destroyed Challenger and Columbia. Optimistic engineers burned people to death in Ford Pintos. It is immoral for engineers to be optimistic. We are obligated to contemplate all the things that can go wrong and prove something will work safely.
You will usually have to prove it to yourselves.
I'm not taking on the burden of proof here.
Let's face it, Chris, you're asking a lot of us.
You want working scientists and engineers to give up safer career opportunities to work on MNT.
You want investors and gov't agencies to put their money into MNT research.
You want policy-makers to leave off worrying about wars, budgets, and elections to decide how to handle MNT.
They're not going to do it unless they see proof. You bear the burden of proof to show that this stuff can have a real impact. Optimism won't cut it. They'll send an engineer to look over your work. If he comes back and says "They neglect this major factor, they assume that thing has a mass of zero when it's got to be at least 20% of the total system, and I can't see the deployment working at all" you won't get an appointment and your issue will be off their agenda. Right now the deck is stacked against you even worse because we just went through a big wave of optimists saying "trust me, this will work out in the end" and a lot of people got burned.
I'm not asking you to do my "homework." I'm offering you a chance to convince me that the "big step" of exponential production can happen. If you're too busy, no problem, I've got other stuff to do too. But if you can't convince me you're going to have a hell of a time convincing the people you need to convince.
Looking at thermionics--doesn't look proven to me. Great stuff if it works, but if it doesn't does the whole nanofactory concept collapse? No, you just have to use some tech that does work, and you should budget for it. There shouldn't be more than one breakthrough on the critical path, that's asking for disaster in a real project. In this case it's asking to be dismissed as an unrealistic handwaver. Given that you put zero as the mass of the cooling system (and other support systems) when calculating the reproduction time for the nanofactory I've still got doubts.
You'll be right far more often if you try to prove to yourself that it will be easy.
I'm not going to take an optimistic attitude looking at this stuff. Optimistic engineers destroyed Challenger and Columbia. Optimistic engineers burned people to death in Ford Pintos. It is immoral for engineers to be optimistic. We are obligated to contemplate all the things that can go wrong and prove something will work safely.
You will usually have to prove it to yourselves.
I'm not taking on the burden of proof here.
Let's face it, Chris, you're asking a lot of us.
You want working scientists and engineers to give up safer career opportunities to work on MNT.
You want investors and gov't agencies to put their money into MNT research.
You want policy-makers to leave off worrying about wars, budgets, and elections to decide how to handle MNT.
They're not going to do it unless they see proof. You bear the burden of proof to show that this stuff can have a real impact. Optimism won't cut it. They'll send an engineer to look over your work. If he comes back and says "They neglect this major factor, they assume that thing has a mass of zero when it's got to be at least 20% of the total system, and I can't see the deployment working at all" you won't get an appointment and your issue will be off their agenda. Right now the deck is stacked against you even worse because we just went through a big wave of optimists saying "trust me, this will work out in the end" and a lot of people got burned.
I'm not asking you to do my "homework." I'm offering you a chance to convince me that the "big step" of exponential production can happen. If you're too busy, no problem, I've got other stuff to do too. But if you can't convince me you're going to have a hell of a time convincing the people you need to convince.
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no subject
Date: 2004-09-21 08:26 am (UTC)http://crnano.typepad.com/crnblog/2004/09/skeptical_on_sk.html#c2192273
Karl, you shifted the sense of the word "optimistic." I was using it in a purely technical sense: Can this technology accomplish that performance?
To shift to talking about risk analysis, then accuse me of being too optimistic, then claim that the less optimistic thing to do is to ignore a claimed risk until it's proved, is broken on many levels.
I'm not trying to convince you to invest in a molecular manufacturing company. I'm trying to convince you that it is plausible that this stuff will work well enough that we should think about planning ahead for it. Are you seriously arguing that no one should spend any attention on it until every detail is proved? That's not responsible at all.
At the moment, we have a bunch of estimates based on theory. They all say that MM will be really, really big. We have a bunch of skeptics based on emotion and politics. They all say we should ignore it. You're now sounding a lot like the politicized skeptics. Theirs is a stupid position, and you're not stupid. What are you reacting to?
By the way, I did not say that thermionics was the only way refrigeration could work. There's also sonic refrigeration: one moving part, no sliding interfaces. Just put 180 dB (?) of sound into a tuned cavity, and one part gets hot while the other gets cold. I haven't looked into this because I've never before seen a suggestion that thermionics won't work. What's your basis for that? Just playing devil's advocate?
There's at least one other refrigeration technology that hasn't been mentioned yet. How much do you want to bet that all four technologies either won't work or will increase the mass of the nanofactory system by more than 5%?
Suppose someone came up with a completely new jet engine technology. Theoretically, it was great. It hadn't yet been demonstrated, and there were some questions about the fuel.
Now if that person went to the President and said "We should pour money into this because it will give us massive military superiority, because it will perform 80% better than today's tech," I would agree that that was premature.
But if that person went to the President and said, "We should study this further because it may be up to 80% better than today's tech once the bugs are worked out, and the Chinese and Indians and Russians are probably already working on it and we're not," I would say that was not premature at all. Would you?
I don't want people to give up their careers to work on MNT. I want people to STOP telling their students not even to read Nanosystems.
And you did take on the burden of proof when you published a criticism of my paper. That criticism was unfounded or actually wrong in almost every detail. You asserted that the refrigerator would weigh too much to allow rapid replication. Prove it, or retract it. You asserted that the small parts would be terribly vibration-sensitive. I pointed out that their resonant frequencies will be in the GHz. Answer me, or retract it.
Chris
Posted by: Chris Phoenix, CRN | September 20, 2004 06:48 PM
no subject
Date: 2004-09-21 08:27 am (UTC)Your abstract, which says the transition from the first assembler to a flood of working products will take "weeks." That's a huge discontinuity in the growth of technology, and that's your justification for pushing for policies to be put in place for MNT before even prototypes are developed. You point to the nanofactory paper as proof that it is that urgent. I don't buy it.
You describe the timeline for producing a block while neglecting assembly time. I think it's going to be greater than 10% of the time, and could be worse depending on how fast the parts can actually be moved.
You describe the number of cycles needed to duplicate a factory but neglect the time to produce the support equipment. Regardless of how much the power plant, cooling plant, etc weigh, they're not going to have a weight of zero.
You claim the time to produce a new nanofactory is mass-driven because it can be unfolded from a 10 cm x 10 cm x 30 cm block to a 1 m x 1 m x 0.5 m assembly but give no detailed explanation or illustration. I think that would be extremely difficult if it's possible at all. I think doing it that way would require adding so many components to enable it that you probably couldn't still fit the whole nanofactory in the 3 product blocks, and it would probably be more difficult than just building much of the factory in its final configuration.
You claim the nanofactory can produce all the parts needed to replicate it but neglect whether the support equipment can be made from hydrocarbons. If one piece can't be built then you don't have exponential production, you have rapid production to the limit set by whatever's making the critical piece.
I add all that together and I don't see a rapid leap to an MNT economy created by the first assembler. You said "weeks." I don't see proof.
I responded to your comments on my post (http://www.livejournal.com/users/selenite/60858.html). I'd rather have the debate there if you want to get into details, since it supports threading. But for your specific questions above:
You asserted that the refrigerator would weigh too much to allow rapid replication.
The support equipment, including the refrigerator, will take time to replicate. You described replication time as only applying to the factory. So including the rest takes longer.
3 + 1 > 3
Does this prevent "rapid" replication by itself? No, but it's not as rapid as you said it'd be.
You asserted that the small parts would be terribly vibration-sensitive. I pointed out that their resonant frequencies will be in the GHz.
Okay, the assemblers proper may not need vibration isolation. But between that scale and the 10.5 cm final product there's going to be a lot of vibration-sensitive operations. If you don't isolate the factory you'll have perfectly good nanoblocks with screwed-up assembly.
Now here's a question for you. I want to make a 1 cm cube starting with six 1 cm x 1 cm x 0.1 cm diamondoid plates fabricated as a 1 cm x 1 cm x 0.6 cm block. How does the block unfold into the cube?